gree_leran/node_modules/webpack/lib/optimize/RemoveParentModulesPlugin.js

205 lines
6.4 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const { STAGE_BASIC } = require("../OptimizationStages");
/** @typedef {import("../Chunk")} Chunk */
/** @typedef {import("../ChunkGroup")} ChunkGroup */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Module")} Module */
/**
* Intersects multiple masks represented as bigints
* @param {bigint[]} masks The module masks to intersect
* @returns {bigint} The intersection of all masks
*/
function intersectMasks(masks) {
let result = masks[0];
for (let i = masks.length - 1; i >= 1; i--) {
result &= masks[i];
}
return result;
}
const ZERO_BIGINT = BigInt(0);
const ONE_BIGINT = BigInt(1);
const THIRTY_TWO_BIGINT = BigInt(32);
/**
* Parses the module mask and returns the modules represented by it
* @param {bigint} mask the module mask
* @param {Module[]} ordinalModules the modules in the order they were added to the mask (LSB is index 0)
* @returns {Generator<Module>} the modules represented by the mask
*/
function* getModulesFromMask(mask, ordinalModules) {
let offset = 31;
while (mask !== ZERO_BIGINT) {
// Consider the last 32 bits, since that's what Math.clz32 can handle
let last32 = Number(BigInt.asUintN(32, mask));
while (last32 > 0) {
let last = Math.clz32(last32);
// The number of trailing zeros is the number trimmed off the input mask + 31 - the number of leading zeros
// The 32 is baked into the initial value of offset
const moduleIndex = offset - last;
// The number of trailing zeros is the index into the array generated by getOrCreateModuleMask
const module = ordinalModules[moduleIndex];
yield module;
// Remove the matched module from the mask
// Since we can only count leading zeros, not trailing, we can't just downshift the mask
last32 &= ~(1 << (31 - last));
}
// Remove the processed chunk from the mask
mask >>= THIRTY_TWO_BIGINT;
offset += 32;
}
}
class RemoveParentModulesPlugin {
/**
* @param {Compiler} compiler the compiler
* @returns {void}
*/
apply(compiler) {
compiler.hooks.compilation.tap("RemoveParentModulesPlugin", compilation => {
/**
* @param {Iterable<Chunk>} chunks the chunks
* @param {ChunkGroup[]} chunkGroups the chunk groups
*/
const handler = (chunks, chunkGroups) => {
const chunkGraph = compilation.chunkGraph;
const queue = new Set();
const availableModulesMap = new WeakMap();
let nextModuleMask = ONE_BIGINT;
const maskByModule = new WeakMap();
/** @type {Module[]} */
const ordinalModules = [];
/**
* Gets or creates a unique mask for a module
* @param {Module} mod the module to get the mask for
* @returns {bigint} the module mask to uniquely identify the module
*/
const getOrCreateModuleMask = mod => {
let id = maskByModule.get(mod);
if (id === undefined) {
id = nextModuleMask;
ordinalModules.push(mod);
maskByModule.set(mod, id);
nextModuleMask <<= ONE_BIGINT;
}
return id;
};
// Initialize masks by chunk and by chunk group for quicker comparisons
const chunkMasks = new WeakMap();
for (const chunk of chunks) {
let mask = ZERO_BIGINT;
for (const m of chunkGraph.getChunkModulesIterable(chunk)) {
const id = getOrCreateModuleMask(m);
mask |= id;
}
chunkMasks.set(chunk, mask);
}
const chunkGroupMasks = new WeakMap();
for (const chunkGroup of chunkGroups) {
let mask = ZERO_BIGINT;
for (const chunk of chunkGroup.chunks) {
const chunkMask = chunkMasks.get(chunk);
if (chunkMask !== undefined) {
mask |= chunkMask;
}
}
chunkGroupMasks.set(chunkGroup, mask);
}
for (const chunkGroup of compilation.entrypoints.values()) {
// initialize available modules for chunks without parents
availableModulesMap.set(chunkGroup, ZERO_BIGINT);
for (const child of chunkGroup.childrenIterable) {
queue.add(child);
}
}
for (const chunkGroup of compilation.asyncEntrypoints) {
// initialize available modules for chunks without parents
availableModulesMap.set(chunkGroup, ZERO_BIGINT);
for (const child of chunkGroup.childrenIterable) {
queue.add(child);
}
}
for (const chunkGroup of queue) {
let availableModulesMask = availableModulesMap.get(chunkGroup);
let changed = false;
for (const parent of chunkGroup.parentsIterable) {
const availableModulesInParent = availableModulesMap.get(parent);
if (availableModulesInParent !== undefined) {
const parentMask =
availableModulesInParent | chunkGroupMasks.get(parent);
// If we know the available modules in parent: process these
if (availableModulesMask === undefined) {
// if we have not own info yet: create new entry
availableModulesMask = parentMask;
changed = true;
} else {
let newMask = availableModulesMask & parentMask;
if (newMask !== availableModulesMask) {
changed = true;
availableModulesMask = newMask;
}
}
}
}
if (changed) {
availableModulesMap.set(chunkGroup, availableModulesMask);
// if something changed: enqueue our children
for (const child of chunkGroup.childrenIterable) {
// Push the child to the end of the queue
queue.delete(child);
queue.add(child);
}
}
}
// now we have available modules for every chunk
for (const chunk of chunks) {
const chunkMask = chunkMasks.get(chunk);
if (chunkMask === undefined) continue; // No info about this chunk
const availableModulesSets = Array.from(
chunk.groupsIterable,
chunkGroup => availableModulesMap.get(chunkGroup)
);
if (availableModulesSets.some(s => s === undefined)) continue; // No info about this chunk group
const availableModulesMask = intersectMasks(availableModulesSets);
const toRemoveMask = chunkMask & availableModulesMask;
if (toRemoveMask !== ZERO_BIGINT) {
for (const module of getModulesFromMask(
toRemoveMask,
ordinalModules
)) {
chunkGraph.disconnectChunkAndModule(chunk, module);
}
}
}
};
compilation.hooks.optimizeChunks.tap(
{
name: "RemoveParentModulesPlugin",
stage: STAGE_BASIC
},
handler
);
});
}
}
module.exports = RemoveParentModulesPlugin;